Fluid heater and method of heating fluid

Abstract

A fluid heater, comprising a tank having an inner chamber for accommodating a fluid to be heated, a heat exchanger having a tube bundle and a shell surrounding the tube bundle, the shell being introduced in the tank so that a wall of the shell is in contact with the fluid in the interior of the tank, the shell having an inlet for introducing a heating fluid, the tube bundle having an outlet which communicates through an upwardly raising pipe with the interior of the tank and an inlet for introducing a fluid to be heated, so that when the heating fluid is introduced through the inlet of the shell into the shell heat of the heating fluid is transferred through the wall of the shell to the fluid in the interior of the tank and also heats the fluid inside the tube bundle so that the heated fluid from the tube bundle is supplied through the upwardly raising pipe into the interior of the tank, providing a heat transfer between the heating and heated fluid by forced and natural convection simultaneously.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims: 
     
       1. A fluid heater, comprising a tank having an inner chamber for accommodating a fluid to be heated; a heat exchanger having a tube bundle and a shell surrounding said tube bundle, said shell being introduced in said tank so that a wall of said shell is in contact with the fluid in the interior of said tank, said shell having an inlet for introducing a heating fluid, said tube bundle having an outlet which communicates through an upwardly raising pipe with the interior of said tank and an inlet for introducing a fluid to be heated, so that when the heating fluid is introduced through said inlet of said shell into said shell heat of said heating fluid is transferred through the wall of said shell to the fluid in the interior of said tank and also heats the fluid inside the tube bundle so that the heated fluid from said tube bundle is supplied through said upwardly raising pipe into the interior of said tank. 
     
     
       2. A fluid heater as defined in claim 1, wherein said tank has an outlet located in a bottom region of said tank and communicating with said inlet of said tube bundle so that a relatively cold fluid from said bottom region of the tank can be supplied into said tube bundle. 
     
     
       3. A fluid heater as defined in claim 2, and further comprising a tampering valve arranged so that the heated fluid is supplied through said outlet of said tank to said tampering valve, and a cold fluid from an external source is supplied to said tampering valve to mix with the heated fluid to thereafter be supplied to a consumer. 
     
     
       4. A fluid heater as defined in claim 1, wherein said inlet of said tube bundle has a pipe communicating with a source of the fluid to be heated. 
     
     
       5. A fluid heater as defined in claim 1, and further comprising a temperature sensor located in said tank and a temperature regulator arranged in a supply line of the heating fluid so as to regulate a supply of the heating fluid sensed by said temperature sensor in dependence on a temperature of the fluid inside said tank. 
     
     
       6. A method of heating fluid in a tank, comprising the steps of arranging in the tank for a heat exchanger having a tube bundle and a shell surrounding said tube bundle, with said shell being introduced in said tank so that a wall of said shell is in contact with the fluid in the interior of said tank; introducing a fluid to be heated into said tube bundle; introducing a heating fluid shell into said shell so that heat of said heating fluid is transferred through a wall of said shell to the fluid in the interior of said tank and also heats the fluid inside the tube bundle; and supplying the heated fluid from said tube bundle through an upwardly raising pipe into the interior of said tank.